Transcript T cells - De Anza College

B.E Pruitt & Jane J. Stein
Chapter 17, part B
Specific Defenses of the Host:
The Immune Response
The Results of Ag-Ab Binding
Figure 17.9
Antibody titer:
• Is the amount of Ab in serum
Figure 17.10
Monoclonal Antibodies
• Hybridomas are produced by fusing a cancer cell with
an Ab-secreting plasma cells
• The hybridoma cell culture is immortal and produces
monoclonal Abs (Mabs)
• Immunotoxins: Mabs conjugated with a toxin to target
cancer cells
• Chimeric Mabs: Genetically modified mice that produce
Ab with a human constant region
• Humanized Mabs: Mabs that are mostly human, except
for mouse antigen-binding
Monoclonal Antibodies
Figure 17.11
Immune system cells communicate via cytokines
• Interleukin-1
Stimulates TH cells
• Interleukin-2
Activates TH, B, TC, and NK cells
• Interleukin-12
Differentiation of CD4 cells
• -Interferon
Increase activity of macrophages
• Chemokines
Cause leukocytes to move to an
infection
Cell-Mediated Immunity
• Specialized lymphocytes, mostly T cells, respond to
intracellular Ags
• After differentiating in the thymus, T cells migrate to
lymphoid tissue
• T cells differentiate into effector T cells when
stimulated by an Ag
• Some effector T cells become memory cells
Pathogens entering the gastrointestinal or
respiratory tracts pass through:
• M (microfold) cells in Peyer's patches which
contains
• Dendritic cells which are antigen-presenting cells
and
• T cells
Dendritic cells present antigens
Figure 17.12
T Cells
• Helper T Cells (CD4, TH)
• T H1
Activate cells related to cell-mediated
immunity
• T H2
Activate B cells to produce eosinophils, IgM,
and IgE
• Cytotoxic T Cells (CD8, TC)
• Destroy target cells with perforin
T Cells
• Delayed Hypersensitivity T Cells (TD)
• Associated with allergic reaction, transplant
rejection, and tuberculin skin test
• Suppressor T cells (TS)
• Turn off immune response when Ag no longer
present
Helper T Cells
Figure 17.13
Cell-mediated Cytotoxicity
Figure 17.14
Nonspecific Cells
• Activated
macrophages:
Macrophages
stimulated by
ingesting Ag or by
cytokines
• Natural killer cells:
Lymphocytes that
destroy virusinfected cells,
tumor
Figure 17.15
T-independent Antigens
B cell
Figure 17.17
T-independent Antigens
Figure 17.16
Antibody-Dependent Cell-Mediated Cytotoxicity
Figure 17.18